Lock



June J. W V F|Tz GERALD LOCK Filed NOV. 5, 1954 Jhn M FIZE-"Ers/ D www 3..

to' a predetermined position. c l

With the above andother objects in view which AppiicarionNcvember-s, laegsfiarNoiprsisrel lf3 l V VS Claims; (01.31.1054@ This invention relatesto improvements in locks and inits broader .aspects is similar to that form-l ing `the subjectmatter ofthe copending application of John W. lFitz Gerald, .SerialNa 751,572,

application, `it is an object of the present invenf tion to provdemeansoperable upon breakage` of afrangible part Veither as a result of percus'sive inward force ora strong outward vpull applied .to the cylinder' during an attempt at vunauthicirized manipulation of thelock for positively rendering the cylinder ineectiveto actuate the mechanism controlled. f Y Y l r '1' i More specifically it isan object of this invention to provide aicylinder lock wherein :the .cyla inder isnormally maintained against endwise movement by a frangible shear pin` adapted to give way. during an `attempt at unauthorized manipulation, to permit 'the cylinder tomove `to a positionlatnwhich other means. secure thelV cylinder'against further actuation. l y

Another object of this inventionresides'in the provision of spring pressed means normally iaintained in a potentially operativecondition to become operative and secure the `loclccylinder against actuation uponniovement ofl the cylinder will appear as thedescription'proceeds,this .ini vention resides in the novel construction, com- Ubination and arrangement of parts substantially as hereinafter @described and more particularly denedjby the appended claims,` it being `understood that such lchanges inthe precise embodiment of the herein disclosedinventi-onmay be f made as come within the scopeofft'he claims.

` The accompanying drawing illustrates one come y incidentaltodriving an implement into the kkeyplete4 example! ofthe physical embodimentv ofthe invention constructed according to the best mode so far devised for the practical a pplication ofthe principles thereof, and `in which: l r

.. Figure lis alongitudinal section View' through `a cylinder lock embodying this invention; 'l f rFigure 2 is a View similar to Figureklybut showi ing thecylinderflocked againstsubsequentfactuation; l` i Figure 3 is a cross section View takenthrough Figure `?'fon the plane ofthe line 3 3; and

Figure 4 is a top viewof the assembled structure taken on a plane perpendicular to the plane on which Figures l and 2 are taken.

Referring now more `particularly to the accompanying drawing, in which like numerals indicate `like parts throughout the several views, the nu- `the ends of the `mei-'all5l`tlesigna'tes the casing or shell of a cylinder lock having a boreI" in which a `lock .cylinder .'l `is"rr'nounted. 1 The lock cylinder iss` inserted into `the shell fromthe rear andbhasa' reduced front l ,l p end portion `8 preferably covered by a hardened p i: As in the invention of the aforesaid copending inetal cap 'Sllprojecting through a correspondingly reduced bore I0. in the` front endf ofthe shell.A

A frangiblel She'aifpin I, I. fixed inthe lock cylinder: 'I` withit's. outerrend portion received in an arcuate l slot I2 holds the cylinder against'end'- wise movement andv through'engagement with slot `I2 A"defines its .normal limits ofrotation." f l Any desired tumbler arrangementmay be employed .to lock they ycylinder `against rotation, and in the present instancewthe cylinder is provided rwi,thailookingbar I-3 projectible from the side of ther cylinder by' :key operable tumblers (not shown) `for engagement in a longitudinal groove inhthe' shell or casingV 5.'` The 'tumblers asis customary,are `retractible by aproperxkey `III inserted into the keyway `I5 of the cylinder "to free the cylinder for rotation.

l Rotationof the cylindermay beg imparted to mechanism tu be controlled through `the medium ofva concentric .cam` I6 `projecting from: its rear end.` n f Y V 1 If-an unauthorized attempt is made to manip--` nlate the lock as` by the insertionof an imple` ment intothe outerend ofthekeyway `and the1 application of` `torsional `force`.there0n,the connection between sucheimplement` and the; keyway to `beadequatetoienable the transmission of thel requisite turninglforce to the cylinder, generally i require'sgthat ztherimplementbe forcibly driven into 'thekeyway a `distance suincient toafford a goodgripl During the application of the percussive yforce wayl'lthe frangibleshear pin `I I gives Vway `and allowsthey cylinder to be driven `inwardly endwise of` the-,shell or casing 5; Uponwsuch endwise intoholes or recesses I8 in `the shellorcasing 5 to positively lock vthe'cylinder against subsequent motionreitherrotational or longitudinal. p p

YIf the unauthorized manipulation of the lockis' attempted throughan outward; pull on the 'cylin-l der and it iszpossible to'apply `a tool to the cylinder for the purpose without shearing the pin II and driving the cylinder inwardly, the outward endwise force on the cylinder will shear off the pin and allow outward endwise displacement of the cylinder. Upon such outward endwisemovement of the cylinder, the locking pins II will again act kshifting of the `cylindentwo `lockingpins II snap to lock the cylinder against subsequent motion,

one of the pins I1 entering the arcuate slot I2 and the other snapping into a hole I8 diametrically opposite one end portion of the slot.

The locking pins I'I are housed within a hardened metal tubular sheath I9 disposed in a bore 20 extending transversely of the cylinder :and are yieldably urged outwardly by an expansive spring 2| confined between the inner ends of the pins. 'Io limit the outward projection of the pins as they engage in their respective holes I8 and also add to the convenience in assembly, the outer ends of the pins are reduced in diameter to provide shoulders 22 which engage inturned flanges 23 on the outer ends of the tubular sheath 20.

When the locking pins I1 snap into their respective holes I8, the cylinder is Vrmly vlocked against actuation even though the proper key be used, and by virtue of the fact that the tubular sheath 20 is formed oihardenedmetal, there is small likelihood of defeating the lock by drilling into the cylinder assuming that the hardened metal cap 8 could be chiseled off.

From the foregoing description taken in connection with the accompanying drawing, it` will be readily apparent to those skilled in the art to which this invention appertains, that this invention affords simple, but highly effective means for preventing unauthorized manipulation of a cylinder lock.

f What I claim as my invention is:

1. In a lock, a bored mounting member, a lock cylinder mounted therein, frangble means to hold the cylinder against endwise displacement in either direction, said means being adapted to give way under apercussive force applied to the cylinder to permit endwise displacement of the cylinder upon the application of percussive force on the cylinder, and means to positively lock the cylinder against rotation andendwise motion upon endwise displacement of the cylinder a predetermined distance. v

2. In a lock, a bored'casing, a lock cylinder rotatable therein in the performance of a normal locking and `unlocking function, a locking pin adapted to interlock the cylinder and the casing upon endwise displacement of the cylinder with respect to the casing a predetermined distance, a spring to automatically move the locking pin to its operative interlocking position, a hardened sheath enclosing the spring and the pin in a manner enabling projection of the pin therefrom, and frangble means engaging-the cylinder and casing to normally hold the cylinder against endwise displacement, said frangble means giving way under an endwise force applied on the cylinder.

3. yIn a lock, a bored casing, a lock cylinderrotatable in the casing to effect a predetermined locking and unlocking function, means normally inactive but operable upon endwise displacement of the cylinder with respect to the casing to a predetermined position to interlock the cylinder and casing and prevent the rotation of the cylinder necessary to effect its locking and unlocking function, and frangble means having engagement with the cylinder and casing to normally define the limits of said rotation of the cylinder and hold the cylinder against endwise displacement, said means giving way under an endwise force applied to the cylinder tov allow endwise displacement of the cylinder to the predetermined position at which the interlocking means secures the ycylinder against further manipulation.

4. In a lock, a bored casing, a lock cylinder rotatable in the casing, means to define the normal limits of rotation of the cylinder and hold the cylinder against endwise displacement including a frangble part adapted to give way under an endwise force whereupon the cylinder is free to move out of its normal position with respect to the casing in the direction of the applied force.

5. In a lock, a bored casing, a lock cylinder mounted therein, a frangble shear pin carried by the cylinder and operating in an arcuate slot in the casing to deiine the normal limits of rotation of the cylinder and hold the cylinder in a normal predetermined endwise position with respect to the casing, said frangible shear pin being adapted to give Way under a percussive force applied on the cylinder to allow endwise displacement of the cylinder from its normal position.

6. `In a lock, a bored casing, a lock cylinder mounted therein, a locking/pin carried by the cylinder and yieldably urged to engage the wall of the casing bore and to snap into a hole in the casing communicating with its bore upon endwise movement of the cylinder a predetermined distance, and frangble means to normally prevent endwise displacement of the cylinder to said predetermined position, said frangble means being adapted to give way under an endwise -force applied'on the cylinder.

'7. In a lock, a bored casing having diametrically opposite holes communicating with its bore, a cylinder mounted in the casing, a locking unit having yiel'dably urged pins carried by the cylinder and normally engaging the wall of the casing bore so as not to interfere with rotation of the cylinder, said pins being adapted to snap into the holes in the casing upon endwise displacementof the cylinder to align the pins with the holes, and frangible means to normally hold the cylinder against endwise displacement, said frangble means being adapted to give way under an endwise force applied on thecylinder.y

8. In a lock, a bored casing having diametrically opposite holes communicating with its bore, a lock cylinder mounted in the casing and having a transverse bore adapted to align with the holes in the casing upon endwise displacement of the cylinder from its normal position, a locking unit mounted in thetransverse bore of the cylinder and comprising a pair of pins, a spring confined between the inner ends of the pins and tending at all times to push the pinsr outwardly of the periphery of the cylinder, a sheath enclosing the pins and the spring, said sheath being snugly received in the transverse bore in the cylinder, the outer ends of the pins being projectible from the sheath, means to limit outward projection of the pins with respect to the sheath, and frangible means to normally hold the cylinder against endwise displacement.

JOHN W. FITZ GERALD. 

